Filler



Aug. 3, 1943.

c. M. WILLIAMS 2,326,085

FILLER Filed Feb. 5, 1941 WITNESSES:

INVENTOR Carrall M Williams.

Patented Aug. 3, 1943 UNITED- Pennsylvania 1 Application February 5,1941,sem na'swnse 3Claims. (o1. inc-116) This invention relates to fillers, and particularly to fillers for use in making insulated joints between electrical conductors.

Heretofore, when conductors were joined, fillers have been employed to cover the joint. Usually a filler is employed adjacent the bare conductors to form a base to which an insulating tape covering can be applied. Many types of fillers have been utilized in attempts to build a covering which will present curved surfaceswat the joint regardless of the angle. at which the conductors are brought together to out down the voltage gradient at the joint, and particularly if the conductors are so joined as to present sharp corners.

Where a fibrous material, such as tape or cloth, is employed as the filler material to build up at the joint a base for the tape, it is substantially impossible to obtain a solid covering about the conductors and voids are formed when the fibrous material is packed about the conductors. Where compositions of matter, such as plastics, are applied as the filler, it is found that the compositions usually set and become hard and are difficult to remove when desired, or are too soft to form a body to which the tape covering can readily be applied. Further, the compositions are generally so sticky that they are difficult to apply, and when applied cannot be readily removed from the conductor, and particularly if the joint is a threaded joint or the like.

It is an object of this invention to provide a filler for use as the body portion of an insulating cover about joints between electrical conductors.

Another object of this invention is to provide a pliable filler of plaster-of-Paris and putty which will not set up hard and which can be readily removed for use as the body portion of a covering about joints of electrical conductors.

Other objects of this invention will become apparent from the following description when taken in conjunction with the accompanying drawing, in which the single figure is a view in elevation, with a part removed, illustrating the filler of this invention applied to a joint between electrical conductors.

Referring to the drawing, there is illustrated a joint between conductors I0, 12 and I4, conductor l4 extending through a suitable insulating bushing 16 and being electrically connected to a bus bar H3. The bushing I6 is supported by any suitable means, such as the flange 20. Since the joint between the conductors is formed with the conductor M at an angle to conductors l and l2, in order to reduce the voltage gradient about the jointand form a base for the tape 24, a filler 22is applied to the ,bared conductors about the jointand is so hand molded that it covers the .,uninsulated portions :of the conductors and is given a curved outer surface. A covering of insulating tape 24 is then applied to the body of filler 22, a coating of varnish (not shown) being associated with the tape 24.

In accordance with this invention, the filler 22 is an intimate mixture of plaster-of-Paris and putty. The mixture comprises from 25% to by volume of plaster-of-Paris and to 50% by volume of putty, the proportions depending upon the amount of oil present in the putty. In- .practice, it is found that an intimate mixture of about 33 /3% by volume of plaster-of-Paris and about 66 by volume of putty of the commercial grade is satisfactory for use as the filler, the commercialgrade of putty having sufficient oil present for cooperating with the plaster-of- Paris in this proportion. V

The filler formed within the proportions given hereinbefore is found to be very satisfactory when employed in making the covering about the joint between the conductors. Within the range of compositions given, it is found that the filler is sufficiently pliable so that it can be formed to a predetermined shape, having the desired curved surfaces when applied to the joint between the conductors. In addition to being pliable when applied to the conductors, it is found that the intimate mixture stiffens within a relatively short time of 2 to 10 minutes to hold the shape imparted to the filler and to maintain the shape as the tape is wound thereon. The filler does not however set up hard as in the case of p1aster-of Paris by itself; Further the filler is not sticky to the hands when hand molded, nor is it dusty, but instead has suflicient adhesive qualities to maintain itself in position about the conductors, while at the same time it is not so adhesive as to prevent its removal from the joint when desired Without clogging threaded joints.

, The putty formed of whitin fullers earth or other selected clays and boiled linseed oil as sold in the open market is particularly adapted to the making of the filler composition of this invention, it being found that when the intimate mixture of the plaster-of-Paris and putty is formed and applied to the conductors the filler effectively increases-the surface area about the joint and since the filler is a semi-conducting material effectively cuts down the voltage gradient and equalizes the stresses. In addition to with reference to a particular embodiment thereof, it is, of course, not to be limited thereto except insofar as is necessitated by the the appended claims.

I claim as my invention: 7

1. A filler for use in making taped joints between electrical conductors composed of an intim-ate mixture of 25% to 50% by Volume of plaster-of-Paris-and 75% to 50% by volume of scope of and boiled linseed oil.

putty, the putty being composed of clay earth and boiled linseed oil.

2. A filler for use in making taped joints between electrical conductors composed of an intimate mixture of about 33 /3% by volume of plaster-of-Paris and about 66%% by volume of putty, the putty being composed of clay earth '3. A filler for use in making taped joints between electrical conductors composed of an intimate mixture of 25% to 50% by volume of plaster-of-Paris and 75% to 50% by volume of putty, the putty being composed of clay earth and boiled linseed oil, the mixture being pliable mg a consistency for holding the shape when so 7 formed.

CARROLL M. WILLIAMS. 

